17G1S steel (17G1S-U)
Designation
Description
17G1S steel is used: for the manufacture of welded structures and components operating under pressure at temperatures from -40 to +475 °C; parts and elements of pipelines of steam and hot water nuclear power plants (NPP), with an estimated temperature not higher than 350 °C at an operating pressure of less than 2.2 MPa (22 kgf/cm2), welded transitions, flanges, welded tees and other fittings of pipelines, as with operating temperature from -40 °C to +350 °C; of electrowelded pryamoshovny pipes of strength group K52 for construction of gas pipelines, oil pipelines and oil pipelines, thermal power plants and heating networks, and gas and oil pipelines increased corrosion resistance of prirodoslovno steel (PL-1, PL-2) with increased resource exploitation; ekspandirovannogo longitudinal electric-welded pipes intended for the construction of high-pressure pipes; spirally welded, of an external diameter of 720, 820, 1020 and 1220 mm with outer anticorrosive coating for operation under pressure up to 7.4 MPa (75 kgf/cm2), intended for pipelines transporting non-corrosive-active gas.
Note
Steel low-alloy silico-manganese. The degree of deoxidation — SP.
Steel 17G1S provides strength grade sheet, universal broadband rental and roll-formed profiles KP 345 with plate thickness of 10 to 20 mm., KP 355 with a thickness up to 10 mm. without the use of additional hardening treatment.
When hardening treatment (reglamentary or controlled rolling or accelerated cooling) comes rolled cross-sections from 20 to 60 mm. of the CP 315 and CP 325, section from 10 to 32 mm. KP 345 and section from 10 to 20 mm. KP 355. In the application of quenching with vacation rentals comes a cross section of 10−20 mm. КП375.
Standards
Chemical composition
According to GOST 19282-73, it is allowed to modify steel with calcium and rare-earth elements from the calculation of the introduction of not more than 0.02% calcium and 0.05% rare-earth elements into the metal.
According to GOST 19281-89 and GOST 19282-73, it is allowed to add aluminum and titanium from the calculation of the mass fraction in the rolled aluminum - no more than 0.050%, titanium - no more than 0.030%.
According to GOST 5520-79, the mass fraction of arsenic can be up to 0.15% in the smelting of steel from the Kerch ore, while the mass fraction of phosphorus should not be more than 0.030%. At the request of the consumer, the mass fraction of sulfur should not exceed 0.025, 0.030 or 0.035%, and phosphorus 0.030 or 0.035%. When steel is smelted in electric furnaces, the mass fraction of nitrogen must be ≤ 0.012%.
According to TU 14-1-1921-76, instead of Ce, Ca≤0.020% can be introduced.
According to TU 14-1-1950-2004, the chemical composition is presented for steel grade 17G1S-U. In the steel grade 17G1S-U produced by JSC MK Azovstal, designed for the production of pipes with a diameter of 1020 mm for the transportation of low-sulfur gas, the mass fraction of sulfur should not exceed 0.007%, phosphorus - 0.020%. For oil and gas pipelines of increased corrosion resistance with increased service life, sheets are manufactured from natural alloy steel grade 17G1S-U:
- the first category - with a mass fraction of chromium and nickel of 0.20-0.50%, phosphorus - not more than 0.030%;
- the second category - with a mass fraction of chromium and nickel of 0.20-0.50%, copper - 0.15-0.35% and phosphorus - no more than 0.030%.
Steel grade 17G1S-Y deoxidized with aluminum and titanium, the total mass fraction of which (on the ladle sample) should be in the range of 0.015-0.075%, with the mass fraction of aluminum should not be more than 0.06%. For globularization of sulfur inclusions, cerium or calcium additive is allowed. The mass fraction of cerium or calcium should not be more than 0.03% and 0.02%, respectively. The carbon equivalent should be no more than 0.46, and for the production of pipes with a diameter of 1020 mm for the transportation of a low-sulfur gas, there should be no more than 0.42.
According to TU 14-3-1138-82 the chemical composition is presented for steel grade 17G1S-U. The chemical composition of steel and the equivalent of carbon are accepted according to the certificate of the supplier of sheet metal. The table shows the permissible residual content of nickel, chromium, copper and aluminum. It is allowed, for globulation of sulfur inclusions, the treatment of steel with additions of cerium (up to 0.03%) and calcium (up to 0.03%), respectively. In individual batches, the manganese content is allowed up to 1.60%, vanadium to 0.10%, nitrogen to 0.02%. It is allowed to supply separate steel melts with a total content of residual aluminum and titanium in the range of 0.010-0.060%, provided that the required mechanical properties are ensured.
According to TU 14-3-1573-96, the chemical composition is given for steel grade 17G1S. Steel grade 17G1S-U has a difference in chemical composition: C ≤ 0.20%, Mn ≤ 1.55%, Si ≤ 0.60%, Al ≤ 0.060%, S ≤ 0.020%, P ≤ 0.025%. The carbon equivalent for both brands is Se ≤ 0.46%. In individual melts of steel grade 17G1S-U is allowed: the mass fraction of manganese to 1.80%, with Se ≤ 0.44; mass fraction of vanadium ≤ 0.10% and (or) niobium ≤ 0.070%. The total mass fraction of aluminum and titanium in the steel grade 17G1S-U should be in the range of 0.015-0.075%.
According to TU 14-158-146-2004, the chemical composition is given for the 1st grade of the ladle test for the pipes of steel grade 17G1S, 17G1S PL-1, 17G1S PL-2, 17G1S-U, intended for the production of pipes of strength class K52 and steel 17G1S-U, for the production of pipes of strength class K55. Niobium and vanadium are optional and are introduced into the steel by calculation with the manufacturer's agreement with the consumer.